The present invention relates to a chassis structure for an electronic system containing a plurality of electronic components therein. More particularly, the present invention provides a composite chassis structure comprising a nonmetal mesh cover formed on one or more surfaces of the metal chassis to obtain additional thermal budget and human-friendly chassis surface.
A chassis in a television, DVD player, or other electronic device has a metal frame on which the circuit boards and other electronic components are mounted. In computers, various components including motherboard, microprocessor, memory, disk drives, and other electronic components are mounted on the chassis. Generally, a computer chassis is composed of a number of panels as shown in FIG. 1. A computer chassis protects all of the vital internal components from dust, moisture, and tampering and is usually made of metal to dissipate heat generated by various electronic components of the computer system.
In its normal operation within a computer, microprocessors (CPU) are the major source of heat dissipation on a computer. If there is no cooling system in the computer, its temperature will reach well over 100° C. If not properly dissipated, the heat generated within the computer can reduce the lifetime of electronic components and also degrade the operation of the components. Heat from a computer may be passively dissipated by warming the outside surface (skin) of the plastic or housing material over the ambient air or actively dissipated through an outlet by using a fan and heat exchanger.
Safety regulations, for example UL-1950, specify different skin temperatures for metal chassis and nonmetal chassis due to the different heat dissipation rate for each chassis. For example, a typical maximum skin temperature of 55° C. is set for a metal chassis, while that of 65° C. is set for a plastic chassis. Accordingly, system manufacturers can obtain additional 10° C. skin temperature margin by adopting a nonmetal chassis. Also, a nonmetal chassis including plastic chassis is more friendly to human skin than a metal chassis.
Conventional chassis is made of either single layered metal or nonmetal material such as plastic. However, nonmetallic chassis is generally not effective in dissipating heat and shielding electromagnetic emissions into the environment surrounding the computer compared with metallic chassis. On the other hand, metal chassis is subject to a much tighter skin temperature allowance by 10° C. compared with nonmetallic chassis as explained above.
As such, it is desirable to devise a new chassis structure where both effective heat dissipation and additional thermal budget in terms of skin temperature can be obtained.